Where commuters walk through remnants of an ancient Greek necropolis.

Large collection from the 3rd millennium BCE.

This 15th-century island fortress later served as home to the executioners no one wanted to live near.

Replicas of Apollo's leonine stone guard cats still line a sacred row in Greece.

A Bronze age settlement on the Greek island of Santorini might have been the inspiration for Plato's Atlantis.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

Giant marble phalluses on the sacred island of antiquity.

This legendary city has been a tourist attraction for centuries.

A 2,000-year-old computer demonstrates remarkable engineering and astronomical precision.

A minotaur, a labyrinth, and a dubious restoration pull in visitors from around the world.

Hidden in a secluded Greek cove is a pristine beach marred only by the rusting smuggler's hulk stranded on its shores.

The hallucinogenic center of the ancient world.

Monasteries on rock pillars, once accessible only by frayed ropes.

Rumored to be the famed pirate's lookout tower, this historic stone structure is now just watching for tourists.

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.

At Chicago's revered Field Museum, visitors are invited to learn about and literally explore DNA.

Years of archaeology, just chillin' by the water cooler.

What's left of the ruins of the 1893 Columbian Exhibition, or World's Fair, also known as the White City.

This unauthorized stone mermaid was secretly carved out of public stone before being permanently preserved.

A gothic church spire sits atop this skyscraper, the tallest church in the world.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

A tiny plaque marks the location of the water source that facilitated the birth of modern-day Boston.

A centuries-old church stands as a testament to Boston's "father of architecture."

What was once a true peninsula has now been filled in, causing the water to recede and leaving many streetside "waterfronts" and landlocked "islands."